Help me solve google webmaster tools Mobile Friendly Issues

Google webmaster tools says i have these issues with my website: Viewport not configured Small font size Touch elements too close Content not sized to viewport Flash usage I'm a software developer and have researched this some and realize that for some errors, its just a matter of adding some html coding to my pages and when you solve it on one page, it solves the problem on all other pages as long as you post the code on all pages, so this should be a pretty simple project for someone that knows what they are doing.